Check your heart rate on your phone

Swiss company CSEM has created the Pulsear device to monitor
ones heart rate while exercising. Pulsear uses a tiny unit embedded in
a regular earphone to see how fast the pulse is by sending the
infrared signals through the tissues in your ear. The result is shown
on an iPhone. Pulsear is based on space technology developed to
examine how astronauts will behave during long space voyages.